1. Field of the Invention
The field of the invention relates to apparatus and methodologies for the transcription of DNA sequence information from autoradiograms into computer data files.
2. Description of the Prior Art
The sequencing of DNA is an essential and often a routine tool in research laboratories in biological and medical sciences. DNA sequence analysis allows identification of the genes, which are the building blocks of hereditary material. DNA sequencing makes possible many powerful new clinical diagnostic techniques. Technologies utilizing DNA sequence information have revolutionized forensic medicine, fetal and neonatal diagnosis, and basic research into the nature of genetic expression.
The need and use for DNA sequencing has created, in turn, a need for an effective device to read DNA sequence information and to store this information into computer file for subsequent analysis. Heretofore, the prior art has devised three types of devices which address this need.
First, automated DNA sequencers have been made which use either fluorescent labeled or radiolabeled DNA probes in combination with light or particle detection devices.
Second, autoradiogram or film digitizers have been developed and rely on charge coupled devices and pattern recognition software to encode and analyze the film data.
Third, sonic location devices have been provided which allow a manual sequencing of autoradiograms.
In each of these prior art approaches the end result is a computer file containing a DNA sequence. This sequence readout typically consists of alphabetic characters A,C,G,T which are abbreviations for the nucleotides adenine, cytosine, guanine and thymine respectively. Typical prior art automated DNA sequencers and autoradiogram digitizers are expensive, costing between $50,000-100,000 in 1990 dollars. In addition, the results produced by those sequencers and digitizers require extensive software analysis. The use of sonic location devices is less expensive, costing approximately 2,500 dollars in present value. However, the limitations of such sonic readers is the reliance on a pointer which must be tapped within a given length, i.e. A,C,G,or T in succession to identify the nucleotide being read. Because gel compression makes it increasingly difficult to identify the next nucleotide band, this necessitates using both a magnifier and a fine cursor line for accurate reading. Both these limitations of a sonic device impede the use of a pointer tapped on a sequence band.
Therefore, what is needed is an apparatus and methodology which is inexpensive yet overcomes the limitations of the less expensive DNA sequencing devices known in the prior art.